Highest temperature in Paris on June 23?

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Active sub-markets

Market context

The real-world event driving this market is the unprecedented heatwave currently engulfing France, with temperatures already soaring to 40°C in some areas and forecasts predicting Paris could hit 40°C this week, a level unprecedented for June. In the last 24 to 48 hours, Meteo France has escalated warnings, placing 59 departments under amber heatwave alerts and predicting a significant temperature rise starting Sunday that will persist through Tuesday, potentially making Monday one of the hottest days ever documented in the nation[5]. This rapid escalation has shifted the crowd-implied probability for the "36°C" outcome to 85%, directly contradicting the 0% YES probability for lower ranges seen in older data snapshots[1].

Historically, June temperatures in Paris have averaged 92°F (roughly 33°C), with daily highs typically ranging between 78°F and 105°F (26°C to 41°C) in recent years[3]. The current forecast, however, resembles the extreme heatwaves of July 2006, where daytime and nighttime temperatures reached record peaks, suggesting a departure from the norm that frames the current high probability for 36°C or above as a rational response to the severe weather conditions[5]. Traders should watch for official updates from Meteo France regarding the duration of the heatwave, as the agency predicts the severe conditions will last at least until Tuesday, with Monday potentially being the peak day[5]. The settlement window ends on 23 June 2026 at 12:00 UTC, meaning the highest temperature recorded for all times on that day at Paris-Le Bourget Airport will determine the outcome, making the timing of the peak heat critical[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on June 23? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On Prediction Today, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Prediction Today is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on Prediction Today?

Zero. Prediction Today routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.